Generally, a disk device, for example, a magnetic disk device includes a magnetic disk which is provided on a base, a spindle motor which supports, rotates, and drives the magnetic disk, and a suspension assembly which supports a magnetic head. The suspension assembly includes a suspension which is attached to a front end portion of an arm, a wiring member (flexure, wiring trace) which is disposed on the suspension, and a load beam. The magnetic head is supported by a gimbal portion of the wiring member, and a head suspension assembly is formed thereby.
Recently, a suspension assembly design has been proposed in which a piezoelectric element (PZT element) that functions as a drive element is mounted near the gimbal portion of the wiring member and micro-displacement is generated in the magnetic head in a seek direction by expansion/contraction operations of the piezoelectric element. According to such a suspension assembly, it is possible to finely control an operation of the magnetic head by controlling a voltage which is applied to the piezoelectric element.
In the suspension assembly design described above, when a piezoelectric element is expanded or contracted, the piezoelectric element is bent in a direction of a thickness thereof, and a plurality of resonance modes can occur therein as a result. As a consequence, positioning accuracy of the magnetic head may decrease.